Continue active follow-up of the presently formed Boston cohorts of DES-exposed and unexposed-sons and daughters in collaboration with the other DES research centers and with NCI staff. "Maintain a high participation rate by updating address changes periodically and mailing informational newsletters to cohort members at two different points in time. [unreadable] Collect new information on covariates and health outcomes during the next five-year period of follow-up. In particular, mail follow-up questionnaires to all cohort members, with different questionnaires for sons, daughters, and grandchildren. Process returned questionnaires for data entry at NCI. Request medical record releases from participants who report key health outcomes and obtain pertinent portions of the medical record for validation of disease. Obtain death certificates for participants who have died. [unreadable] Initiate and direct specific analyses (e.g., analyses of breast cancer and benign breast disease, breast size, endometriosis, body mass index) of study wide data collected during the contract period and previously. Prepare manuscripts on these findings in collaboration with other DES investigators. Participate actively in the development of reports and manuscripts led by other DES investigators. [unreadable] Assist in planning new DES research initiatives in collaboration with the other DES investigators and scientific staff at NCI.